i started my loader today- and after it warmed up a bit at an idle i tested the emergency shutdown on the blower-all it did was slow the motor down a little- i worked the flap back and forth a couple times and it still didn't kill the motor. i reset it and then gave the motor about 1/3rd throttle and tried the shutdown again---still the same--won't kill the motor--just slows it down some----anyone know what i should be attempting? would putting a ball valve inline before the fuel filter be enough? if you can cut off the fuel and its not sucking the engine oil and burning it--would'nt that work in case of a runaway?-hopefully one would never happen-but if it did and the flapper does not work i doubt if i could either choke off the air cleaner(paper type) or get the air cleaner hose off in time.
The intake air has got to be choked off to kill the engine. Is the valve worn away inside?
If the flap is closing fully with a good seal the shaft seals might be sucked out of the blower. That wouls let in air. Later Bob
We never used to test them with the engine running, just because you can do more harm than good, as mentioned, it can suck in the seals on the blower rotors. We tested them with engine shutdown, if flap slams shut.. all good. A fuel valve would be a good secondary shutdown, heard many stories about guys smashing fuel fittings off with hammers to shut down a runaway 2 banger. If you tune them as per the book, shouldn't have any problems with a runaway situation. Every runaway I saw or heard of, was due to some nitwit doing something wrong. Of course I'm not saying it can't happen, just my experiences. I had a 16v149 runaway on me 50 hours after a rebuild. Scared the crap outa me shutting it down. had to climb up on side of it to get to rear shutdown flap.There were 2 electric solenoids for auto shutdown of flaps, which were linked together via rods and linkages. the rear one had a failed solenoid so it had to be activated by hand. That poor girl was screaming like a 149 never should. Had to replace all cyl heads, tore the valve bridge posts clean out of nearly all the heads. When I ran past the control box 9this was a genset) i glanced at tacho - 2500 and rising!
Yair . . . Zed that 149 gen.set runaway wasn't in North Qld by any chance? Cheers
i never trust the old GM's ALWAYS had a bit of tin next to the air intake first time you fire it up after any major work I had one fire up to life 6V92 in a ford louiville and it scared the sh&t outa me and another guy, NO FUEL LINES OR FILTERS ON IT, turned it over on the key to check after an inframe and it took off We worked out there was a guts full of kero sitting in the blower box which it spun up on (lucky we had the tin handy)
I have heard that most Detroits ranaway from an injector rack that jammed. around 1980 they added spring loaded fuel control levers. Later Bob
Rare ss has it right. The only way you will shut down a runaway detroit is to choke the air supply. Either with rags, sheet metal, wood, mud flap. You can use a co2 fire extinguisher also
Scrub Puller, it was at Gunpowder copper mine. NW Qld, north of Mt Isa. Maybe around 97' or 98 I think... We always had a service manual at the ready whenever we fired them up after major work, so we could slam it over intake of blower/turbo. Best way to snuff 'em. rare SS, good fun getting the rh rocker cover off? (if it had Jakes...) We had to fix a 16v92 that another shop had in-framed. Not sure how, but they'd managed to mix up the fuel rods to racks. So it fired up, rod got jammed in cyl head and away she went...
Yair . . . . Gotcha Zed I heard the boys had a runaway with the V-16 after I left the Karumba power-house it was all pretty hush hush and I never got the full story. . . just thought I might have fluked a lead when you mentioned it. LOL Cheers
There is a mesh screen inside the intake before the blower. The blower flap shuts against it when you activate it in a shutdown. The mesh has gasket material around the outside. I have heard if the mesh is around the wrong way, the flap wont seal against it properly and cause the engine to slow down but not stop. This is because the flap is against the mesh only, and not against the gasket material. Someone else might be able to give a better description of this if they have had one apart recently.
one funny thing I saw was at Tech school (TAFE) we had a Dyno room with a bunch of motors and some transmissions and a acouple of Dyno's.. some of the guys in my class where stalling down an old GM when one of them thought it'd be a good idea to see if the emergencey shutdown flap would work under full load The old girl dropped down to around 40rpm but didnt quite stall and he let the flap go and she got a huge guts of fuel and air and went to some huge rpm which sent them all into a panic and they ran out of the room like a bunch of schoolgirls haha The lecturer walked over and shut it down calm as and called them a bunch of clowns.. lol happy days
Its been my experience that the flap won't shut them off, but will keep them at a low idle or at least keep them from a full on runaway untill you can get them shut off through other means.